In many electronic housings, in which space is at a premium, control functions are often consolidated in a single control knob. For example, a rotary knob which has several rotational positions for activating several electronic functions may be combined with a push button switch, which may have only one function for turning the electronics on/of functions. While enabling multiple control functions of the electronics in the housing, the conventional rotary-push button control complicates the assembly of the housing and makes replacement of the control knob difficult. Additionally, the complex housing needed for conventional rotary-push button controls prevents the use of more complex, multi-functional rotary-push buttons knobs.
A conventional control knob assembly typically requires protrusion into the housing of the electronics, in order to transmit the various controls to the electronics. The protrusion creates an opening into the housing which may allow environmental contamination and electromagnetic interference (EMI) into the electronics.
To mitigate the risks associated with environmental contamination and EMI, operator control knobs of this type have utilized O-rings, gaskets, or other applied sealants. This, in turn, may be messy and may further complicate the assembly or maintenance of the control knob. Furthermore, because the control knob requires a protruding member to be inserted into the housing, the protruding member occupies a portion of the internal volume of the housing which may be better used for other purposes.
As will be explained, the present invention provides a rotary knob assembly that has advantages over conventional rotary knob assemblies, because the rotary knob assembly of the present invention does not require any intrusion into the housing, nor direct contact with the internal electronics of the housing. As will be described, the present invention provides a push button and dual rotary knob assembly which contactlessly controls an electronic device, without protrusion into the housing of the electronics and without direct contact with the electronics.